1-phenylpyrazole-4,5-dicarboxylic acid derivatives, composition containing them, and pollen formation inhibiting method of using them

ABSTRACT

Pollen formation in cereal grain plants is inhibited by application of a 4,5-dicarboxy or 5-carboxamido-4-carboxy (or derivatized carboxy)-1-(3,5-disubstitutedphenyl)pyrazole. Use of the compounds facilitates the production of hybrid seed.

CROSS-REFERENCE

This application is a continuation of application Ser. No. 013,520 filedon Feb. 11, 1987 now abandoned which is a continuation-in-part ofco-pending application No. 947,139, now abandoned, filed Dec. 29, 1986,which is a continuation-in-part of co-pending application No. 841,405,filed Mar. 19, 1986 now abandoned.

FIELD OF THE INVENTION

This invention belongs to the fields of plant hybridization and organicchemistry, particularly, agricultural chemistry. Very importantimprovements in the hardiness and yield of cultivated plants,particularly grains, have been made by the technique of hybridization.In the past, hybridizing those species, in which each plant producesboth pollen and pollen-receiving organs, has been very difficult.

Compounds have been found which are capable of inhibiting formation ofpollen. The use of such a compound greatly simplifies hybridization.Plants of the two strains to be crossed are simply planted adjacent toone another, as in long, relatively narrow plots, and the plots of oneof the strains are treated with a pollen formation inhibitor. All of theseed produced by the treated plants will be hybrid seed, originatingfrom pollen contributed by the untreated plants, if the pollen formationinhibitor is perfectly effective.

Compounds having pollen formation inhibiting activity have been taughtin the past by Fujimoto, U.S. Pat. No. 4,345,934, by McNulty and Warner,U.S. Pat. No. 4,147,528, and by Carlson, U.S. Pat. No. 4,238,220.

SUMMARY OF THE INVENTION

This invention provides a series of pollen formation inhibitingpyrazoles of the formula ##STR1## wherein

R and R¹ independently represent chloro, bromo or methyl;

R² is hydroxy, C₁ -C₄ alkoxy, C₃ -C₄ alkenoxy, C₃ -C₄ alkynoxy, or aphytologically-acceptable moiety forming a salt of the carboxylic acid;

R³ is NH₂, hydroxy, or a phytologically-acceptable moiety forming a saltof the carboxylic acid;

or R² and R³ combine to form an imide;

provided that R³ is NH₂ when R² is alkoxy, alkenoxy or alkynoxy; andthat R² and R³ are the same when R³ is other than NH₂.

The invention also provides pollen formation inhibiting compositionswhich comprise a compound of the above formula and one or morephytologically-acceptable diluents. The invention also provides a methodof inhibiting pollen formation in a cereal grain plant which issensitive to such treatment comprising supplying to the plant at a timeprior to anther formation a pollen formation inhibiting amount of acompound of the above formula.

Further, the invention provides a method of producing hybrid cerealgrain seed having a male and a female parent variety, comprisingplanting seed of said male and female parent varieties in separate plotsadjacent to each other, treating the female parent plants growing fromsaid female parent seed with a pollen formation inhibiting method asjust described, said female parent variety being sensitive to suchtreatment, allowing said treated female parent plants to be pollinatedby the male parent plants growing from said male parent seed and toproduce hybrid seed, and harvesting said hybrid seed from the treatedfemale parent plants.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In this document, all temperatures are described degrees Celsius. Allexpressions of percentage, proportion and the like are in weight unitsunless otherwise stated.

In the above formula, the terms C₁ -C₄ alkoxy includes bothstraight-chain and branched alkyl groups such as methyl, ethyl, propyl,isopropyl, butyl, t-butyl and isobutyl linked through an oxygen atom.

The term C₃ -C₄ alkenoxy includes such unsaturated groups as allyl and2-methylallyl, linked through an oxygen atom. The term C₃ -C₄ alkynoxyincludes such groups as propargyl and 3-butynyl, linked through anoxygen atom.

The salts of the above formula are formed with anyphytologically-acceptable moiety capable of forming a salt of thecarboxylic acid. The preferred salt-forming moieties include alkalimetals, amine groups, and quaternary ammonium groups. More particularly,sodium, potassium, lithium, C₁ -C₄ alkylamino, dialkylamino andtrialkylamino groups and quaternary ammonium groups wherein the nitrogenatom is substituted with four hydrogen, C₁ -C₁₈ alkyl, phenyl or benzylmoieties are preferred. Bulky quaternaary ammonium groups having one ortwo C₁₀ -C₁₈ groups are more preferred.

For example, quaternary ammonium groups such as ammonium,tetramethylammonium, diethyl-dimethylammonium, diethyl-dibutylammonium,benzyl-trimethylammonium, t-butyltrimethylammonium,phenyl-triethylammonium, diethyl-dipropylammonium,s-butyl-trimethylammonium, isobutyl-triethylammonium,dimethyl-bis(tetradecyl)ammonium, trimethyl-octadecylammonium,diethyl-dodecyl-pentadecylammonium, dimethyl-decyl-heptadecylammoniumand the like are useful and may be chosen for convenience in thecircumstances. Further, such amines as methylamine, butylamine,triethylamine, dipropylamine and the like are convenient for saltformation.

Certain classes of the compounds of the present invention are preferred.The preferred classes are as follows. It will be understood that groupsmay be chosen from the preferred classes and may be combined in anydesired combination to create further, more limited or more extensivepreferred classes.

(1) R² is hydroxy or a salt thereof;

(2) R² is hydroxy;

(3) R² is alkoxy;

(4) R² is methoxy;

(5) R² is alkenoxy or alkynoxy;

(6) R and R¹ are the same;

(7) R and R¹ are chloro;

(8) R and R¹ are methyl;

(9) R and R¹ are chloro or bromo;

(10) R² and R³ are hydroxy or a salt thereof;

(11) R³ is NH₂.

The following compounds of the invention are mentioned to assure thatthe reader understands the invention.

4-carboxy-1-(3,5-dibromophenyl)-5-pyrazolecarboxamide.

1-(3-bromo-5-methylphenyl)-4-propoxycarbonyl-5-pyrazolecarboxamide.

4,5-dicarboxy-1-(3,5-dibromophenyl)pyrazole, dipotassium salt.

1-(3-chloro-5-methylphenyl)-4-isopropoxycarbonyl-5-pyrazolecarboxamide.

4-ethoxycarbonyl-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamide.

4-t-butoxycarbonyl-1-(3-chloro-5-methylphenyl)-5-pyrazolecarboxamide.

1-(3,5-dichlorophenyl)-4-isobutoxycarbonyl-5-pyrazolecarboxamide.

4-allyloxycarbonyl-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamide.

4,5-dicarboxy-1-(3,5-dimethylphenyl)pyrazole.

4,5-dicarboxy-1-(3-bromo-5-methylphenyl)pyrazole, disodium salt.

4,5-dicarboxy-1-(3,5-dibromophenyl)pyrazole, bis(triethylamine) salt.

4-allyloxycarbonyl-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide.

1-(3,5-dichlorophenyl)-4-(2-methylallyl)oxycarbonyl-5-pyrazolecarboxamide.

4-allyloxycarbonyl-1-(3,5-dibromophenyl)-5-pyrazolecarboxamide.

1-(3,5-dimethylphenyl)-4-(2-methylallyl)oxycarbonyl-5-pyrazolecarboxamide.

4-(2-butenyl)oxycarbonyl-1-(3,5-dibromophenyl)-5-pyrazolecarboxamide.

4,5-dicarboxy-1-(3-chloro-5-methylphenyl)pyrazole, bis(triethylamine)salt.

4-(3-butenyl)oxycarbonyl-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide.

1-(3-bromo-5-chlorophenyl)-4-propargyloxycarbonyl-5-pyrazolecarboxamide.

1-(3-bromo-5-methylphenyl)-4-propargyloxycarbonyl-5-pyrazolecarboxamide.

1-(3-bromo-5-chlorophenyl)-4-(2-butynyl)oxycarbonyl-5-pyrazolecarboxamide.

1-(3-bromo-5-mehtylphenyl)-4-(1-methylpropargyl)oxycarbonyl-5-pyrazolecarboxamide.

4,5-dicarboxy-1-(3-chloro-5-methylphenyl)pyrazole.

1-(3-chloro-5-methylphenyl)-4,5-pyrazoledicarboximide.

1-(3,5-dimethylphenyl-4,5-pyrazoledicarboximide.

1-(3,5-dibromophenyl)-4,5-pyrazoledicarboximide.

1-(3,5-dichlorophenyl)-4,5-pyrazoledicarboximide.

4,5-dicarboxy-1-(3,5-dichlorophenyl)pyrazole, bis(tetrabutylammonium)salt.

4,5-dicarboxy-1-(3-chloro-5-bromophenyl)pyrazole,bis(hexadecyl-trimethylammonium) salt.

4,5-dicarboxy-1-(3,5-dimethylphenyl)pyrazole,bis(undecyl-triethylammonium) salt.

1-(3-chloro-5-methylphenyl)-4,5pyrazoledicarboximide.

1-(3-bromo-5-methylphenyl)-4,5-pyrazoledicarboximide.

1-(3-bromo-5-chlorophenyl)-4,5-pyrazoledicarboximide.

4-carboxy-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide, sodium salt.

1-(3,5-dibromophenyl)-4-carboxy-5-pyrazolecarboxamide, potassium salt.

4-carboxy-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide, lithium salt.

4-carboxy-1-(3-chloro-5-methylphenyl)-5-pyrazolecarboxamide,triethylamine salt.

4-carboxy-1-(3-chloro-5-methylphenyl)-5-pyrazolecarboxamide, methylaminesalt.

4-carboxy-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide, butylamine salt.

4-carboxy-1-(3,5-dibromophenyl)-5-pyrazolecarboxamide, triethylaminesalt.

4-carboxy-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamide, triethanolaminesalt.

4-carboxy-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide,tetrabutylammonium salt.

4-carboxy-1-(3-chloro-5-methylphenyl)-5-pyrazolecarboxamide,benzyl-triethylammonium salt.

1-(3-bromo-5-methylphenyl)-4-carboxy-5-pyrazolecarboxamide,dibutyl-diethylammonium salt.

4-carboxy-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamide,tetramethylammonium salt.

4-carboxy-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamide,dimethyl-bis(dodecyl)ammonium salt.

4-carboxy-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide,dimethyl-methyl-octadecylammonium salt.

4-carboxy-1-(3,5-dibromophenyl)-5-pyrazolecarboxamide,heptadecyl-trimethylammonium salt.

4-carboxy-1-(3-bromo-5-methylphenyl)-5-pyrazolecarboxamide,dimethyl-propyl-tetradecylammonium salt.

1-(3,5-dibromophenyl)-4-carboxy-5-pyrazolecarboxamide,dimethyl-bis(pentadecyl)ammonium salt.

The compounds of the present invention are prepared by a basic processwhose first step is the reaction of an aryl hydrazine with an alkyl(alkoxymethylene)cyanoacetate to prepare the corresponding5-amino-1-phenyl-4-1H-pyrazolecarboxylate. Next, the aminopyrazole isconverted to the corresponding 5-halopyrazolecarboxylate, which is thenconverted to the 5-cyanopyrazolecarboxylate. That compound is the keyintermediate for the preparation of the present pollen formationinhibitors.

In the key step of the basic process, the 5-cyano-4-pyrazolecarboxylateis hydrolyzed with a strong base, preferably with potassium hydroxide,to prepare the desired 4-carboxy-5-pyrazolecarboxamide. The reactionscheme is illustrated below. ##STR2##

In the above scheme, the term Alk refers to C₁ -C₄ alkyl groups, and theterm Halo refers to chloro or bromo.

All of the steps of the processes described in this document proceed inacceptable yields without the use of unusual excess quantities of anyreactant. In general, equimolar quantities can be used with satisfactoryresults. However, as is usual in organic reactions, it is preferable andadvisable to use an excess amount of reactants which are inexpensive oreasy to obtain, in order to assure full utilization of reactants whichare expensive or difficult to obtain. Similarly, the steps of theprocess may be allowed to proceed for a long period of time, to maximizeyield of the desired product, or may be halted before the reaction iscomplete, to maximize throughout of product from the system. Eithermanner of operating a process may be preferable, depending on thecircumstances.

In the first step of the above scheme, it is most preferred to use alower alkanol as the reaction solvent. The preferred reactiontemperature is elevated, in the range of about 50°-150°. It will beunderstood that temperatures above the boiling point of the reactionmixture may be used at elevated pressures. However, the reactions willgo at any reasonable temperature, such as about 0°-200°, if appropriateoperating care is used.

The halogenation step of the above scheme is preferably carried out withnitrosyl chloride as both the diazotizing and halogenating agent,resulting in a 5-chloropyrazole. It is conventional to use nitrosylchloride as a gas, by bubbling it through the vigorously mixed reactionmixture. The present chlorination is carried out in any non-reactiveorganic solvent, most preferably in a halogenated alkane such aschloroform, carbon tetrachloride and the like. Moderate temperatures inthe range of 0°-50° are preferred, in order to maximize the solubilityof nitrosyl chloride in the reaction mixture.

5-Bromopyrazole intermediates are prepared with an alkyl nitrite as thediazotizing agent, and an appropriate halogen source. Isoamyl nitrite,t-butyl nitrite and the like are appropriate diazotizing agents, andbromoform and elemental bromine are convenient sources of bromine. Thereaction conditions are substantially the same as those forchlorinations.

Cyanation of the 5-halopyrazole is carried out in a conventional mannerwith an alkali metal cyanide, such as sodium cyanide, lithium cyanide orpotassium cyanide. The cyanation can be done in inert organic solventsof which aprotic solvents are preferred. For example, diemthylformamide,dimethylsulfoxide and hexamethylphosphoramide are particularly preferredsolvents in this step. It is preferred to cyanate at elevatedtemperatures in the range of about 50°-200°, most preferably about80°-140°.

The hydrolysis step, which prepares the 4-carboxy-5-pyrazolecarboxamide,is most conveniently carried out with potassium hydroxide in aqueousethanol. Conventionally, the base is dissolved in a minimum amount ofwater, and added to ethanol to prepare the reaction medium. Othe alkalimetal hydroxides, such as sodium hydroxide and lithium hydroxide, arealso useful for the process. Similarly, other reaction solvents besidesaqueous ethanol are useful, particularly other aqueous alkanols such asmethanol, propanol and isopropanol. The hydrolysis is preferably carriedout at a moderately elevated temperature in the range of about 50°-100°,most preferably at the reflux temperature of the reaction mixture.

Alternatively, the hydrolysis may be done with aqueous hydrobromic acid,at moderately elevated temperatures, such as 50°-100°. Continuedhydrolysis with hydrobromic acid will hydrolyze the carboxamide groupand prepare the dicarboxy compound. The dicarboxy compounds can thus bemade in a single step from the 5-cyano-4-pyrazolecarboxylate, or can bemade in a separate step from the 4-carboxy-5-pyrazolecarboxamide.

An improved method of preparing certain alkylaryl hydrazines,particularly phenylhydrazines having a 3-methyl substituent, is carriedout by reacting the corresponding aniline with sodium nitrite to preparethe diazonium salt, and reacting the salt with potassium sulfite asdescribed in Houben-Weyl, Methoden der Organische Chemie, Vol. 10/2, p.180 (1967). The preparation below illustrates the preparation of an arylhydrazine by the process just described.

An alternative process for the present compounds, which is preferable insome instances, begins with the 5-aminopyrazole-4-carboxylate. Thatintermediate is reacted with dimethyldisulfide in the presence oft-butyl nitrite in an inert organic solvent at a moderate temperature.Ambient temperature is quite satisfactory. The amino group of theintermediate is replaced by a methylthio group in that step. The sulfuratom of the methylthio group is then oxidized, to form a methylsulfonylgroup, with an oxidizing reagent such as hydrogen peroxide. Theoxidation is preferably carried out at a moderately elevated temperaturein acetic acid.

The methylsulfonyl group of that intermediate is replaced with a nitrilegroup by reaction with an alkali metal cyanide at an elevatedtemperature, and the nitrile group is then hydrolyzed to form the amideas described in the outline of the basic process above.

The imides of the present invention are readily made by treating a4-carboxy-5-pyrazolecarboxamide with a coupling agent at an elevatedtemperature. As shown in examples below, the preferred coupling agent iscarbonyldiimidazole. Temperatures in the range of about 50°-150° aresatisfactory, at normal or elevated pressure.

Salts of the 4-carboxy-5-pyrazolecarboxamides, or the4,5-dicarboxypyrazoles, are readily prepared in the usual ways, as bycontacting the compound with the appropriate base in an aqueous alkanolor aqueous ketone. When an alkali metal salt is desired, the base can beany appropriate alkali metal hydroxide, alkoxide, carbonate orbicarbonate. When a quaternary ammonium salt is to be made, theappropriate quaternary ammonium halide, sulfonate, hydroxide,methanesulfonate or the like is combined with the sodium salt of thecarboxy compound in a suitable organic solvent. Salts are formed atmoderate temperatures in the range of 0°-100°.

Compounds wherein the 4-carboxy group has been esterified are easilyprepared in the usual manner, by reacting the 4-carboxy compound withthe appropriate alcohol in an organic solvent, in the presence of asmall amount of a mineral acid as esterification catalyst. Esters arealso prepared by reacting an alkali metal salt of the acid with a halideof the ester group to be added. Moderate temperatures in the range of50°-100° are quite satisfactory, and the reaction times are usuallybrief. Coupling agents may be used to assist esterifications but are notusually necessary.

The following preparation and examples are shown further to assist thereader in preparing the compounds of the present invention.

PREPARATION 1 3,5-dimethylphenylhydrazine, hydrochloride

To a 3-necked round-bottomed flask were added 250 ml of concentratedhydrochloric acid and 185 g of ice. To that mixture was added, over aperiod of 25 minutes, 100 g of 3,5-dimethylaniline. That mixture washeld between 0°-5° and stirred for 15 minutes after the addition, andthen a solution of 72 g of sodium nitrite in 230 ml of ice-water wasadded over 45 minutes while the mixture was held between -5° and 0°.

Meantime, a potassium sulfite solution was prepared by bubbling sulfurdioxide through a solution of 317 g of potassium hydroxide in 1,100 mlof water at 20°-30°. Sulfur dioxide was added to a final pH of 4. Thesolution was then cooled to 0°.

To the sulfite solution was added the diazonium salt mixture, and themixture was heated to 85° and stirred for 1 hour at that temperature. Itwas then filtered while hot through a glass wool plug, and the filtratewas stirred while it cooled overnight to ambient temperature. It wasthen filtered, and the solids were dried in air overnight to obtain 185g of crude product. It was dissolved in denatured ethanol andcrystallized out by addition of water.

The product was then added to 875 ml of concentrated hydrochloric acidand 1,750 ml of ice-water. The mixture was heated to 75° and stirred for30 minutes to form the hydrochloride salt. The reaction mixture wasfiltered hot, and stirred while cooling to ambient temperatureovernight. The solids were collected by filtration and dried at 60° toobtain 39 g of the desired intermediate.

EXAMPLE 1 4-carboxy-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamide

A 38.6 g portion of the intermediate prepared in Preparation 1 wascombined with 37.9 g of ethyl (ethoxymethylene)cyanoacetate, 36.7 g ofsodium acetate and 300 ml of ethanol, and the reaction mixture washeated under reflux for 20 hours. It was then poured into 1 liter ofice-water with stirring, and the mixture was filtered. The solids weredried, and were recrystallized from ethanol/water, with charcoal, toobtain 40.8 g of ethyl5-amino-1-(3,5-dimethylphenyl)-4-pyrazolecarboxylate, m.p. 113°-114°.

A 30.6 g portion of that intermediate was added to 180 ml of chloroform,and 22.2 g of dimethyldisulfide was added. When the reactants haddissolved, 4.6 g of t-butyl nitrite was added at ambient temperature.The mixture warmed spontaneously to 35°, and another 4.6 g of thenitrite was added. That addition raised the temperature to 55°. Thereaction temperature was maintained near 50° by addition of 1 mlportions of additional nitrite for one hour, until a total of 18.3 g ofnitrite had been added. The mixture was then allowed to stir overnightwhile it cooled. The mixture was then washed twice with water and oncewith brine, and it was then dried using phase separation paper andsodium sulfate. The volatiles were then removed under vacuum to obtain34.5 g of an oily residue. A 10.2 g portion of that residue was purifiedby high performance liquid chromatography, eluting with 3:1 hexane:ethylacetate, to obtain 8.23 g of an oily product which was essentially pureethyl 1-(3,5-dimethylphenyl)-5-methylthio-4-pyrazolecarboxylate.

A 7.3 g portion of the above intermediate was added to 30 ml of aceticacid and 15 ml of 30% hydrogen peroxide, and the mixture was heated on asteam bath for 105 minutes. It was then cooled overnight and filtered.The solids were washed with water and dried to obtain 5.6 g of ethyl1-(3,5-dimethylphenyl)-5-methylsulfonyl-4-pyrazolecarboxylate, m.p.120°-121.5°.

A 5.0 g portion of the above intermediate was combined with 35 ml ofdimethylformamide and 1.9 g of sodium cyanide, and the mixture washeated to 80°-90° and held for 30 minutes. It was then stirred overnightwhile it cooled, and was poured into 100 ml of ice-water. The solidswere separated by filtration and dried, and were recrystallized fromethanol/water to obtain 3.14 g of ethyl5-cyano-1-(3,5-dimethylphenyl)-4-pyrazolecarboxylate, m.p. 83.5°-84.5°.

A 2.5 g portion of the above intermediate was added to 25 ml of ethanol,and 1.6 g of potassium hydroxide was added. The mixture was heated underreflux for 10 minutes, 7 ml of water was added, and the mixture washeated under reflux for 1.5 hours. It was then poured into 100 ml ofwater, and the mixture was made acid with hydrochloric acid. The mixturewas chilled overnight, and was filtered. The solids were dried,dissolved in 2N sodium hydroxide and made acidic with hydrochloric acid.The solids were collected, and were recrystallized from 400 ml of waterto obtain 1.42 g of the desired product, m.p. 223°-225°.

Theory: C, 60.23; H, 5.05; N, 16.21; Found: C, 60.39; H, 4,89; N, 15.92.

EXAMPLE 2 4-carboxy-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide

Twenty-five g of 3,5-dichlorophenylhydrazine, hydrochloride was added to200 ml of ethanol, 18 g of sodium acetate and 18.6 g of ethyl(ethoxymethylene)cyanoacetate. The mixture was heated under reflux for20 hours, and was poured into 700 ml of ice-water. The mixture wasfiltered, and the solids were dcried and recrystallized from ethanol toobtain 28.5 g of ethyl5-amino-1-(3,5-dichlorophenyl)-5-pyrazolecarboxylate, m.p. 157°-158°.

A 14.2 g portion of the above intermediate was added to 140 ml ofchloroform, and to the mixture were added 8.9 g of dimethyldisulfide and3.6 g of t-butyl nitrite at ambient temperature. A total of 3.6 g moreof the nitrite was added in portions, and the mixture was then stirredovernight at ambient temperature. It was then washed twice with waterand once with brine and was dried and evaporated under vacuum. Theresulting oil was chromatographed with 7:2 hexane:ethyl acetate, and theproduct was recrystallized from hexane to obtain 10.0 g of ethyl1-(3,5-dichlorophenyl)-5-methylthio-4-pyrazolecarboxylate, m.p. 70°-72°.

A 9.3 g portion of that intermediate was oxidized with 20 ml of 30%hydrogen peroxide in 40 ml of acetic acid, as shown in Example 1, toobtain 7.6 g of ethyl1-(3,5-dichlorophenyl)-5-methylsulfonyl-4-pyrazolecarboxylate, m.p.179°-181°.

A 7.0 g portion of the above intermediate was added to 60 ml ofdimethylformamide and 2.4 g of sodium cyanide and reacted as shown inExample 1 to obtain 5.7 g of ethyl1-(3,5-dichlorophenyl)-5-cyano-4-pyrazolecarboxylate, m.p. 101°-103°.

A 2.02 g portion of the above intermediate was dissolved in 40 ml ofethanol, and 1.1 g of potassium hydroxide was added. The mixture wasstirred under reflux for 15 minutes, 20 ml of water was added, and themixture was stirred under reflux for 80 minutes. It was then poured into150 ml of water and filtered, and the filtrate was made acid withhydrochloric acid. The acidic solution was chilled overnight andfiltered, and the solids were dried and recrystallized from aqueousacetic acid to obtain 1.4 g of the desired product, m.p. 258°-260° dec.

Theory: C, 44.03; H, 2.35; N, 14.00; Found: C, 44.27; H, 2.29; N, 13.93.

EXAMPLE 3 4-methoxycarbonyl-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamide

A 1.1 g portion of the compound of Example 1 was suspended in 20 ml ofmethanol and hydrogen chloride gas was bubbled through the mixture for 1minute. The mixture was then heated under reflux for 2 hours, and waspoured into 50 ml of ice-water. The aqueous mixture was made basic withsodium hydroxide and was filtered, and the solids were dried undervacuum and recrystallized from toluene to obtain 0.14 g of the desiredproduct, m.p. 179°-180°.

Theory: C, 61.53; H, 5.53; N, 15.38; Found: C, 61.76; H, 5.40; N, 15.11.

EXAMPLE 4 4-carboxy-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamide, sodiumsalt

Two g of the compound of Example 1 was suspended in 20 ml of methanol,and 0.4 g of sodium methoxide was added slowly with stirring. Thesolution was filtered and evaporated to dryness under vacuum, and theresidue was recrystallized from methanol/diethyl ether and dried undervacuum to obtain 0.65 g of the desired salt, m.p. 266°-268°.

Theory: C, 55.52; H, 4.30; N, 14.94; Found: C, 55.27; H, 4.49; N, 14.66.

EXAMPLE 5 4-carboxy-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamide,dimethyl-bis(C₁₀ -C₁₄ alkyl)ammonium salt

A 3.13 g portion of the compound of Example 1 was slurried in 60 ml of50% aqueous acetone, and 0.48 g of sodium hydroxide was added. Themixture was warmed, and to it was added 7.48 g of Kemamine Q (HumkoChemical Division of Witco Chemical Company), a 75% solution ofdimethyl-bis(C₁₀ -C₁₄ alkyl)ammonium chloride. The mixture was stirredovernight at ambient temperature, and the acetone was then removed undervacuum. The aqueous suspension was extracted with 100 ml ofdichloromethane, and the organic layer was dried over sodium sulfate andevaporated under vacuum to obtain 7.28 g of the desired product in theform of an oil. It was identified by elemental and nuclear magneticresonance analysis.

Found: C, 70.82; H, 11.14; N, 7.35.

NMR in CDCl₃ : δ 7.95 (s, 1H); 7.22 (s, 2H); 6.92 (s, 1H); 3.05-3.40 (m,4H); 3.19 (s, 6H); 2.33 (s, 6H); 0.7-1.7 (m, 49H).

EXAMPLE 6 1-(3,5-dimethylphenyl)-4,5-pyrazoledicarboximide

Two g of the compound of Example 1 was dissolved in 15 ml ofdimethylformamide, and 1.38 g of carbonyl diimidazole was added. Themixture was heated on the steam bath for 3 hours, and was then pouredinto 150 ml of ice-water. The mixture was filtered, and the solids weredried under vacuum and recrystallized from acetic acid to obtain 0.88 gof the desired product, m.p. 233°-235°.

Theory: C, 64.72; H, 4.60; N, 17.42; Found: C, 64.34; H, 4.57; N, 17.12.

EXAMPLE 7 1-(3,5-dichlorophenyl)-4-methoxycarbonyl-5-pyrazolecarboxamide

A 1.5 g portion of the compound of Example 2 was suspended in 30 ml ofmethanol, and hydrogen chloride gas was bubbled through the suspensionfor 1 minute.

Then 30 ml of methanol was added over a 5 minute period while theaddition of gas was continued. Then the mixture was heated under refluxfor 2 hours, and was cooled and filtered. The solids were collected anddried to obtain 1.15 g of the desired product, m.p. 220°-222°.

Theory: C, 45.88; H, 2.89; N, 13.38; Found: C, 46.09; H, 3.06; N, 13.51.

EXAMPLE 8 1-(3,5-dichlorophenyl)-4-ethoxycarbonyl-5-pyrazolecarboxamide

Two g of the compound of Example 2 was suspended in 80 ml of absoluteethanol and hydrogen chloride gas was bubbled through for 5 minutes. Themixture was then heated under reflux for 2 hours and cooled, and wasthen filtered. The solids were collected and dried to obtain 1.25 g ofthe desired product, m.p. 164°-166°.

Theory: C, 47.58; H, 3.38; N, 12.80; Found: C, 47.49; H, 3.38; N, 12.69.

EXAMPLE 9 4-carboxy-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide, sodiumsalt

A 2.5 g portion of the compound of Example 2 was slurried in 25 ml ofmethanol, and 0.45 g of sodium methoxide was added with stirring. Alittle more methanol was added, and the mixture was heated on the steambath for a few minutes. It was then cooled and filtered, and thefiltrate was evaporated under vacuum to obtian the impure product, whichwas dissolved in hot methanol, treated with charcoal and precipitatedwith diethyl ether to obtain 1.26 g of the desired product, m.p.278°-280°. The product was identified by nuclear magnetic resonanceanalysis.

NMR in DMSOd₆ : δ 7.98 (s, 1H); 7.72 (s, 1H); 7.56 (s, 2H).

EXAMPLE 10 4-carboxy-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide,dimethyl-bis(C₁₀ -C₁₄ alkyl)ammonium salt

Five g of the compound of Example 2 was slurried in 100 ml of 50%aqueous acetone, and 0.67 g of sodium hydroxide was added. The mixturewas warmed, and 10.35 g of Kemamine Q was added. The mixture was thenstirred overnight at ambient temperature, and the acetone was removedunder vacuum. The aqueous residue was extracted with dichloromethane,and the organic layer was evaporated under vacuum to obtain 11.3 g of anoil, which was identified as the desired product by elemental andnuclear magnetic resonance analysis.

Found: C, 63.98; H, 9.43; N, 7.13.

NMR in CDCl₃ : δ 8.00 (s, 1H); 7.24 (s, 3H); 3.05-3.55 (m, 10H); 0.7-1.7(m, 54H).

EXAMPLE 11 4-carboxy-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide,octadecyl-trimethyl ammonium salt

Five g of the compound of Example 2 was slurried in 100 ml of 50%aqueous acetone, 0.67 g of sodium hydroxide was added, and the mixturewas warmed and stirred for 15 minutes. Then 10.6 g ofoctadecyl-trimethylammonium chloride, 50% solution, was added and themixture was stirred overnight. It was then extracted with 100 ml ofethyla acetate, and the organic layer was washed with brine and driedwith sodium sulfate and phase separation paper. The extract was thenevaporated under vacuum to obtain 9.95 g of the desired product, m.p.141°-144°. It was identified by elemental and nuclear magnetic resonanceanalysis.

Found: C, 60.55; H, 8.62; N, 8.44.

NMR in CDCl₃ : δ 8.04 (s, 1H); 7.32 (s, 1H); 7.28 (s, 2H); 3.08-3.44 (m,11H); 0.7-1.7 (m, 38H).

EXAMPLE 12 1-(3,5-dichlorophenyl)-4,5-pyrazoledicarboximide

Four g of the compound of Example 2 was dissolved in 40 ml ofdimethylformamide, and 2.38 g of carbonyldiimidazole was added. Themixture was stirred briefly, and was then heated on the steam bath for 3hours. It was then poured into 200 ml of ice-water, and the mixture wasfiltered. The solids were dried and recrystallized from aceticacid-water to obtain 1.67 g of the desired product, m.p. 210°-212°.

Theory: C, 46.84; H, 1.79; N, 14.90; Found: C, 47.07; H, 1.75; N, 14.85.

EXAMPLE 13 4,5-dicarboxy-1-(3,5-dichlorophenyl)pyrazole

A suspension of 6.25 g of ethyl5-cyano-1-(3,5-dichlorophenyl)-4-pyrazolecarboxylate in 100 ml of 48%hydrobromic acid was stirred at reflux for 41/2 hours. The mixture wascooled and filtered, and the solids were dried and recrystallized fromtoluene to obtain 3.25 g of the desired product, m.p. 205° dec.

Theory: C, 43.88; H, 2.01; N, 9.30; Found: C, 44.03; H, 2.28; N, 9.39.

The following reports of biological tests illustrate the efficacy of thepresent invention.

Test I

The test was begun by planting Waldron wheat seeds in 4 inch pots, 4seeds per pot, in a sterilized sandy-loam soil. The wheat was allowed togrow in a favorable greenhouse environment, and the plants were treatedwith a test compound about 24 days after the seed was planted. Eachcompound was formulated for testing by dissolving the proper amount,depending on the concentration to be tested, in 5 ml of 1:1 by volumeacetone:denatured alcohol, containing 10% by volume of polysorbate 20.Compounds which did not dissolve were finely dispersed in the solvent.The organic mixture was then diluted to 30 ml with deionized water atabout ambient temperature, and the aqueous dispersion was evenly sprayedover the foliage of two pots of wheat. Untreated control plants wereprovided in each experiment.

The results of the tests are reported below as the number of seed perspikelet. The number of seed per spikelet in a normal plant is about 1.5to 2.5. In the tables below, the results of replicate experiments havebeen averaged. When the results of an experiment were not different fromthe results of the contemporaneous untreated controls, the inactivity isindicated merely by "N".

                  TABLE I                                                         ______________________________________                                        Compound of    Concentration                                                  Example No.    ppm         Result                                             ______________________________________                                        1               10         N                                                                  25         0.73                                                               50         0.03                                                               50         1.08                                                               50         N                                                                  50         0.00                                                               63         0.74                                                              100         0.00                                                              100         N                                                                 100         0.46                                                              125         0.01                                                              150         0.00                                                              150         0.17                                                              150         0.00                                                              200         0.00                                                              200         N                                                                 200         N                                                                 200         N                                                                 200         N                                                                 200         0.44                                                              200         0.00                                                              250         0.00                                                              400         0.00                                                              400         0.02                                                              400         0.15                                                              400         0.00                                                              500         0.50                                                              500         0.01                                                              600         0.00                                                              600         0.07                                                              600         0.00                                                              1000        0.00                                                              1000        0.00                                               2               10         1.61                                                               25         1.40                                                               50         0.00                                                               50         0.86                                                               50         0.42                                                               50         N                                                                  63         0.35                                                               63         0.45                                                              100         0.00                                                              100         0.58                                                              100         0.33                                                              125         0.08                                                              125         0.09                                                              150         0.00                                                              150         0.09                                                              150         0.00                                                              200         0.00                                                              200         0.07                                                              200         N                                                                 200         N                                                                 200         N                                                                 200         0.03                                                              200         0.00                                                              250         0.00                                                              250         0.11                                                              400         0.00                                                              400         0.03                                                              400         0.07                                                              400         0.00                                                              500         0.01                                                              500         0.48                                                              500         0.00                                                              600         0.00                                                              600         0.11                                                              600         0.00                                                              1000        0.00                                                              1000        0.02                                               3               50         0.03                                                              150         N                                                                 200         N                                                                 400         0.10                                                              600         0.19                                                              1000        0.00                                               4               50         N                                                                  50         0.00                                                              150         N                                                                 150         0.00                                                              200         N                                                                 200         0.00                                                              400         N                                                                 400         0.00                                                              600         N                                                                 600         0.00                                                              1000        N                                                                 1000        0.00                                               5               25         0 39                                                               50         0.28                                                              100         0.16                                                              200         0.00                                                              400         0.00                                                              600         0.00                                                              800         0.00                                               6               50         N                                                                  50         N                                                                 150         0.83                                                              150         N                                                                 200         0.49                                                              200         0.00                                                              400         0.12                                                              400         0.00                                                              600         0.00                                                              600         0.00                                                              1000        0.00                                                              1000        0.00                                               7               50         N                                                                 100         0.74                                                              150         0.00                                                              200         0.38                                                              400         0.00                                                              500         0.31                                                              600         0.27                                                              1000        N                                                  8               50         0.36                                                              150         0.59                                                              200         0.13                                                              400         1.24                                                              600         0.36                                                              1000        0.29                                                               50         0.20                                                               50         0.00                                                              150         0.14                                                              150         0.00                                                              200         0.10                                                              200         0.00                                                              400         0.04                                                              400         0.00                                                              600         0.06                                                              600         0.00                                                              1000        0.00                                                              1000        0.00                                               10              25         0.83                                                               50         0.19                                                              100         0.71                                                              200         0.00                                                              400         0.00                                                              600         0.00                                                              1000        0.00                                               11              50         N                                                                 150         0.00                                                              200         0.00                                                              400         0.00                                                              600         0.00                                                              1000        0.00                                               12              50         1.83                                                              150         1.53                                                              200         1.35                                                              400         0.82                                                              600         0.77                                                              1000        0.39                                               ______________________________________                                    

Test II

The tests reported below were carried out in the same way as thosereported in Test I, except that the formulated compounds were applied tothe soil in which the wheat plants grew, rather than to the foliage.Applications were made about 21 days after the seed was planted.

                  TABLE II                                                        ______________________________________                                        Compound of       Rate                                                        Example No.       lb/A   Result                                               ______________________________________                                        1                 0.19   0.74                                                                   0.38   0.22                                                                   0.47   0.00                                                                   0.75   0.45                                                                   0.94   0.00                                                                   1.5    0.08                                                                   1.88   0.00                                                                   3      0.11                                                                   3.75   0.00                                                                   6      0.40                                                 2                 0.19   1.84                                                                   0.38   0.93                                                                   0.47   0.00                                                                   0.47   0.00                                                                   0.75   0.27                                                                   0.94   0.00                                                                   0.94   0.00                                                                   1.5    0.12                                                                   1.88   0.00                                                                   1.88   0.00                                                                   3      0.15                                                                   3.75   0.00                                                                   3.75   0.00                                                                   6      0.00                                                 ______________________________________                                    

Test III

The following tests were carried out in the same manner as those of TestI, except that the compounds were supplied in the form of formulations,the formulae of which are listed below in the Compositions section ofthis document.

                  TABLE III                                                       ______________________________________                                        Compound of            Concentration                                          Example No.                                                                              Composition ppm         Result                                     ______________________________________                                        1          1            63         0.88                                                              125         0.00                                                              250         0.03                                                              500         0.00                                       2          2            63         0.49                                                              125         0.06                                                              250         0.00                                                              500         0.00                                       ______________________________________                                    

Test IV

The tests reported below were carried out in the same manner as those ofTest II, except that the compounds were supplied as formulatedcompositions, and two varieties of wheat were used. The data arereported in the table below in the same manner described in Test I.

                  TABLE IV                                                        ______________________________________                                        Cmpd. of Compo-                Rate                                           Ex. No.  sition      Variety   lb/A Result                                    ______________________________________                                        1        1           Waldron   0.47 0.00                                                                     0.94 0.00                                                                     1.88 0.00                                                                     3.75 0.00                                               3           Yolo      0.5  1.00                                                                     1.0  0.94                                                                     2.0  0.08                                                           Waldron   0.5  1.70                                                                     1.0  0.91                                                                     2.0  1.02                                      2        2           Waldron   0.47 0.00                                                                     0.94 0.00                                                                     1.88 0.00                                                                     3.75 0.00                                               4           Yolo      0.5  1.41                                                                     1.0  0.37                                                                     2.0  0.19                                                           Waldron   0.5  1.06                                                                     1.0  0.59                                                                     2.0  0.20                                      ______________________________________                                    

Test V

Tests which were substantially similar to those of Test I were carriedout on barley. The applications of compounds were made about 21 daysafter the barley seeds were planted. The results were as follows.

                  TABLE V                                                         ______________________________________                                        Cmpd. of           Concentration                                              Ex. No.    Variety ppm             Result                                     ______________________________________                                        1          Poco    12.5            N                                                             25              N                                                             50              N                                                             100             N                                                             200             N                                                             400             N                                                             1000            0.43                                                  Barcott 12              N                                                             25              N                                                             50              N                                                             100             N                                                             200             N                                                             400             N                                                             1000            0.00                                       2          Poco    12.5            N                                                             25              N                                                             50              N                                                             100             0.16                                                          200             0.31                                                          400             0.10                                                          1000            0.12                                                  Barcott 12              N                                                             25              N                                                             50              N                                                             100             N                                                             200             N                                                             400             0.00                                                          1000            0.00                                       ______________________________________                                    

Test VI

Tests with barley were carried out according to the method of Test IIabove; the compounds were applied to the soil about 21 days after thebarley seeds were planted.

                  TABLE VI                                                        ______________________________________                                        Cmpd. of             Rate                                                     Ex. No.              lb/A         Result                                      ______________________________________                                        1            Poco    0.19         N                                                                0.38         N                                                                0.75         N                                                                1.5          N                                                                3            0.00                                                             6            0.10                                                             15           0.00                                                     Barcott 0.19         N                                                                0.38         N                                                                0.75         N                                                                1.5          0.04                                                             3            0.18                                                             6            0.02                                                             15           0.00                                        2            Poco    0.19         N                                                                0.38         N                                                                0.75         N                                                                1.5          0.39                                                             3            N                                                                6            0.49                                                             15           0.10                                        2            Barcott 0.19         N                                                                0.38         N                                                                0.75         N                                                                1.5          0.15                                                             3            0.08                                                             6            0.02                                                             15           0.01                                        ______________________________________                                    

Test VII

The tests reported below were carried out on barley. The compounds wereprovided int he form of formulated granular compositions, which wereapplied at the time the seeds were planted, by mixing the granules intothe top few millimeters of soil in each pot.

                  TABLE VII                                                       ______________________________________                                        Cmpd. of  Compo-               Rate                                           Ex. No.   sition   Variety     lb/A Result                                    ______________________________________                                        1         3        Bonanza     0.5  0.33                                                                     1.0  0.41                                                                     2.0  0.32                                                         Gateway     0.5  0.01                                                                     1.0  0.26                                                                     2.0  0.50                                                         Poco        0.5  0.18                                                                     1.0  0.10                                                                     2.0  0.42                                      2         4        Bonanza     0.5  0.09                                                                     1.0  0.49                                                                     2.0  0.00                                                         Gateway     0.5  0.15                                                                     1.0  0.02                                                                     2.0  0.01                                                         Poco        0.5  0.17                                                                     1.0  0.25                                                                     2.0  0.14                                      ______________________________________                                    

Test VIII

Golden Midget corn seeds were planted in pots, and the plants were grownin the greenhouse. Applciations of compounds of the invention were madein the form of foliar sprays, about 15 days after the seeds wereplanted. In some tests, the compounds were applied in the form ofdispersions such as were described in Test I above; in other tests, thecompounds were in the form of formulated compositions. Concentrations ashigh as 10,300 ppm were tested. In all cases, foliar spray applicationsfailed to produce sterile pollen from the treated plants.

Test IX

Further tests on corn were carried out in the greenhouse, by applyingthe compounds to the soil in the 8-inch pots in which the plants grew,2-3 days after the seeds were planted. In some cases, the compounds wereformulated as described in Test I, and in others, they were in the formof compositions described in the Compositions section below. When thecompounds were inactive, and the treated plants produced viable pollen,the fact is indicated in the table below by "N". Activity, observed assterile pollen, is indicated by a "A", and, in some instances, furtherobservations about the condition of the treated plants. In all tests,the corn was of the Golden Midget variety.

                  TABLE IX                                                        ______________________________________                                        Cmpd. of            Rate                                                      Ex. No. Composition mg/pot   Result                                           ______________________________________                                        1       1           7.5      N                                                                    15       A Sterile tassel                                                     20       A Sterile tassel                                                     25       A Sterile tassel                                                     30       A Sterile tassel                                                     10       A Good ear                                                           20       A Reduced seed                                                       40       A Reduced seed                                                       10       A Stunted ears                                                       20       A Good ear                                                           40       A Slt. ear injury                                        3           4.5      N                                                                    9.1      A Pollen not viable                                                  18.1     A Sterile tassel                                                     36.3     A No anthers                                                         72.6     A No tassel                                                          4.5      N                                                                    9.1      N                                                                    18.1     A Sterile tassel                                                     36.3     A Sterile tassel                                                     72.6     A Sterile tassel                                                     4.5      N                                                                    9.1      A No anthers                                                         18.1     A Sterile tassel                                                     36.3     A Sterile tassel                                 1       3           72.6     A Sterile tassel                                         Test 1      10       N                                                                    20       A Few anthers                                                        40       A No tassel                                                          10       N                                                                    20       A Sterile tassel                                                     40       A No tassel                                                          10       A Damaged tassel                                                     20       A Sterile tassel                                                     40       A No tassel                                                          10       N                                                                    20       A Sterile tassel                                                     40       A Sterile tassel                                                     4.2      N                                                                    8.5      N                                                                    17       A No tassel or injured                                                        tassel                                           2       Test 1      9.1      N                                                                    18.1     N                                                                    36.3     N                                                                    72.6     N                                                                    10       N                                                                    20       N                                                                    40       N                                                2       4           20       N                                                                    40       N                                                                    60       N                                                                    20       N                                                                    40       N                                                                    60       A Sterile tassel                                         2           20       N                                                                    40       N                                                                    60       N                                                                    20       N                                                                    40       N                                                                    60       N                                                        Test 1      4.5      N                                                                    9.1      N                                                                    18.1     A Damaged tassel                                                     36.3     N                                                                    72.6     N                                                                    4.5      N                                                                    9.1      N                                                                    18.1     N                                                                    36.3     N                                                                    72.6     N                                                3       Test 1      10       A No tassel                                                          40       A No tassel                                      4       Test 1      10       N                                                                    20       N                                                                    40       A Damaged tassel                                                     10       N                                                                    20       A No tassel                                                          40       A Damaged tassel                                 5       Test 1      10       N                                                                    20       N                                                                    40       N                                                                    10       N                                                                    20       N                                                                    40       A No tassel                                                          10       N                                                                    20       N                                                                    40       A Slow tassel                                                        10       N                                                                    20       N                                                                    40       A Slow tassel                                    ______________________________________                                    

Tests of compounds 5-12, substantially like those applied to thecompound of Example 5, showed no activity.

Test X

The experiment described here was a field experiment carried out incentral Indiana, U.S.A. The experiment was started in planting strips ofPioneer and Caldwell wheat in the autumn. The field was fertilized atthe time of planting, and the wheat was planted in long strips of a fewrows each, adjacent to one another, so that pollen could readily betransferred from one group of plants to another.

The test compounds were those of Examples 1 and 2, formulated asCompositions 1 and 2, respectively. The compounds were applied dilutedin water, as foliar sprays. Volume rates of 50 and 100 gallons per acrewere used, as shown in the table below.

One application of compound was made to each test plot. Applicationswere made on 9 different dates, all in the month of April, following theplanting of the wheat.

The test plots were laid out in the bands of wheat, and they became thefemale plots for the production of hybrid wheat. Each test plot was 6rows×13 feet in size.

At the time of wheat head emergence, some heads in each treated plotwere bagged with small glassine bags. Five heads in each row of eachtest plot were bagged.

When the seed was formed, the number of seeds per spikelet in the baggedplants gave a measure of the extent to which pollen formation wasinhibited, because those seed could have been formed only byself-pollination. Thus, the number of seeds per spikelet is a measure ofthe degree of hybridization which could occur. If the number is zero,then complete hybridization will occur. If the number is larger, betweenzero and the number of seeds per spikelet in the control plants, thedegree of hybridization is correspondingly reduced.

In the table below, the results are reported as the number of seeds perspikelet in the bagged heads. Only the results from the main shoots ofeach plant are considered; tiller results are not reported. The averageresults for a large number of untreated control plots are also given foreach variety of wheat.

                  TABLE X                                                         ______________________________________                                        Cmpd. of   Rate   Volume                                                      Ex. No.    lb/A   gal/A       Date Result                                     ______________________________________                                        Caldwell Wheat                                                                Control (mean of 13 plots)                                                                             1.74                                                 1          0.25    50         1    0.22                                                                     2    0.36                                                                     3    0.82                                                                     4    0.73                                                                     5    1.45                                                                     6    0.07                                                                     7    0.16                                                                     8    0.00                                                                     9    0.05                                                         100         1    1.45                                                                     2    0.82                                                                     3    0.61                                                                     4    1.35                                                                     5    1.31                                                                     6    0.61                                                                     7    0.09                                                                     8    0.12                                                                     9    0.00                                                  0.5     50         1    0.05                                                                     2    0.52                                                                     3    0.57                                                                     4    0.10                                                                     5    0.59                                                                     6    0.00                                                                     7    0.35                                                                     8    0.00                                                                     9    0.00                                       1          0.5    100         1    0.36                                                                     2    0.02                                                                     3    0.27                                                                     4    0.23                                                                     5    0.24                                                                     6    0.00                                                                     7    0.00                                                                     8    0.00                                                                     9    0.00                                                  1       50         1    0.00                                                                     2    0.00                                                                     3    0.01                                                                     4    0.00                                                                     5    0.00                                                                     6    0.00                                                                     7    0.01                                                                     8    0.21                                                                     9    0.00                                                         100         1    0.00                                                                     2    0.12                                                                     3    0.00                                                                     4    0.05                                                                     5    0.00                                                                     6    0.01                                                                     7    0.00                                                                     8    0.00                                                                     9    0.00                                       1          2       50         1    0.00                                                                     2    0.00                                                                     3    0.00                                                                     4    0.01                                                                     5    0.01                                                                     6    0.01                                                                     7    0.01                                                                     8    0.01                                                                     9    0.09                                                         100         1    0.00                                                                     2    0.00                                                                     3    0.00                                                                     4    0.00                                                                     5    0.00                                                                     6    0.00                                                                     7    0.01                                                                     8    0.00                                                                     9    0.00                                       2          0.25    50         1    0.73                                                                     2    1.13                                                                     3    1.06                                                                     4    1.59                                                                     5    1.41                                                                     6    1.43                                                                     7    1.03                                       2          0.25    50         8    0.40                                                                     9    0.55                                                         100         1    1.02                                                                     2    1.52                                                                     3    1.92                                                                     4    1.62                                                                     5    1.86                                                                     6    1.09                                                                     7    0.89                                                                     8    0.11                                                                     9    0.64                                                  0.5     50         1    0.97                                                                     2    0.60                                                                     3    0.89                                                                     4    1.61                                                                     5    1.60                                                                     6    1.07                                                                     7    0.94                                                                     8    0.55                                                                     9    0.40                                                         100         1    1.05                                                                     2    1.05                                                                     3    1.37                                                                     4    2.10                                                                     5    1.89                                                                     6    0.49                                       2          0.5    100         7    0.37                                                                     8    0.62                                                                     9    0.84                                                  1       50         1    0.44                                                                     2    0.69                                                                     3    0.23                                                                     4    0.71                                                                     5    1.65                                                                     6    1.10                                                                     7    0.45                                                                     8    0.39                                                                     9    0.34                                                         100         1    0.68                                                                     2    1.30                                                                     3    0.86                                                                     4    1.08                                                                     5    2.16                                                                     6    --                                                                       7    0.47                                                                     8    0.01                                                                     9    0.04                                                  2       50         1    0.12                                                                     2    0.50                                                                     3    0.28                                                                     4    0.05                                                                     5    0.13                                                  2       50         6    0.40                                                                     7    0.60                                                                     8    0.15                                                                     9    0.42                                                         100         1    0.63                                                                     2    0.26                                                                     3    0.54                                                                     4    0.22                                                                     5    0.66                                                                     6    0.20                                                                     7    0.25                                                                     8    0.10                                                                     9    0.03                                       Pioneer Wheat                                                                 Control (mean of 14 plots)                                                                             1.56                                                 1          0.25    50         1    1.31                                                                     2    1.12                                                                     3    1.07                                                                     4    1.61                                                                     5    1.76                                                                     6    0.80                                                                     7    0.57                                                                     8    0.71                                                                     9    0.59                                                         100         1    1.46                                                                     2    1.64                                                                     3    1.13                                                                     4    1.28                                                                     5    1.91                                                                     6    1.48                                                                     7    0.85                                                                     8    0.32                                                                     9    0.32                                                  0.5     50         1    0.32                                                                     2    1.30                                                                     3    1.01                                                                     4    0.69                                                                     5    1.08                                                                     6    0.21                                                                     7    0.76                                       1          0.5     50         8    0.12                                                                     9    0.04                                                         100         1    1.33                                                                     2    0.42                                                                     3    0.97                                                                     4    1.07                                                                     5    1.14                                                                     6    0.33                                                                     7    0.05                                                                     8    0.01                                                                     9    0.00                                                  1       50         1    0.02                                                                     2    0.05                                                                     3    0.17                                                                     4    0.01                                                                     5    0.05                                                                     6    0.00                                                                     7    0.05                                                                     8    0.00                                                                     9    0.00                                                         100         1    0.41                                                                     2    0.25                                                                     3    0.61                                                                     4    0.45                                                                     5    0.02                                       1          1      100         6    0.22                                                                     7    0.03                                                                     8    0.02                                                                     9    0.00                                                  2       50         1    0.00                                                                     2    0.00                                                                     3    0.03                                                                     4    0.01                                                                     5    0.00                                                                     6    0.00                                                                     7    0.01                                                                     8    0.00                                                                     9    0.01                                                         100         1    0.00                                                                     2    0.00                                                                     3    0.08                                                                     4    0.01                                                                     5    0.02                                                                     6    0.00                                                                     7    0.00                                                                     8    0.00                                                                     9    0.00                                       2          0.25    50         1    0.73                                                                     2    1.38                                                                     3    1.05                                                                     4    1.78                                                                     5    1.83                                                                     6    1.43                                                                     7    0.75                                                                     8    0.55                                                                     9    0.70                                                         100         1    1.45                                                                     2    1.05                                                                     3    0.67                                                                     4    1.50                                                                     5    1.61                                                                     6    1.42                                                                     7    0.71                                                                     8    0.27                                                                     9    0.60                                                  0.5     50         1    1.15                                                                     2    0.73                                                                     3    0.95                                                                     4    1.51                                                                     5    1.23                                                                     6    0.73                                                                     7    0.78                                                                     8    0.29                                                                     9    0.41                                       1          0.5    100         1    1.18                                                                     2    1.36                                                                     3    0.84                                                                     4    1.56                                                                     5    1.63                                                                     6    0.55                                                                     7    0.33                                                                     8    0.51                                                                     9    0.43                                       2          1       50         1    0.55                                                                     2    0.57                                                                     3    0.45                                                                     4    0.96                                                                     5    1.28                                                                     6    0.64                                                                     7    0.87                                                                     8    0.10                                                                     9    0.15                                                         100         1    1.11                                                                     2    1.01                                                                     3    0.46                                                                     4    1.08                                                                     5    1.61                                                                     6    0.25                                                                     7    0.33                                                                     8    0.23                                                                     9    0.10                                       2          2       50         1    0.52                                                                     2    0.59                                                                     3    0.38                                                                     4    0.69                                                                     5    0.36                                                                     6    0.61                                                                     7    0.51                                                                     8    0.00                                                                     9    0.40                                       2          2      100         1    0.92                                                                     2    0.40                                                                     3    0.92                                                                     4    0.27                                                                     5    0.64                                                                     6    0.32                                                                     7    0.21                                                                     8    0.07                                                                     9    0.00                                       ______________________________________                                    

Test XI

This test was carried out by formulating compounds as shown in Test I,and applying the formulations to 4-inch pots of Waldron wheat.Applications were directly to the soil, about 16 days after the seedswere planted. The results are reported below in the manner of Table Iabove.

                  TABLE XI                                                        ______________________________________                                        Compound of       Rate                                                        Example Number    mg/pot  Result                                              ______________________________________                                         8                1       0.00                                                                  0.5     0.00                                                                  0.25    0.42                                                                  0.12    0.23                                                13                1       0.00                                                                  0.5     0.30                                                                  0.25    N                                                                     0.12    N                                                   ______________________________________                                    

Test XII

Several compounds were tested on Golden Midget corn in the greenhouse.Plants were grown in 8" pots. The compounds were formulatedsubstantially as shown in Test I, and the formulations were diluted sothat the amounts shown in the table below were each applied in 50 mltotal volume. Applications were made to the soil, two days afterplanting.

As the plants matured, the development of the tassel and silk were ratedon a scale where 0 indicated no development, and 100 indicated normaldevelopment. Even the controls did not develop normally, it will benoted, because of the greenhouse conditions. The time, in days afterplanting, when the anthers extruded was also noted. The followingresults were observed; all are means of three replicates.

                  TABLE XII                                                       ______________________________________                                        Cpd. of   Rate    Tassel     Silk  Anther                                     Ex. No.   mg/pot  Devel.     Devel.                                                                              Extrusion                                  ______________________________________                                        1         1.88    86.7       35.0  47.3                                                 3.75    46.7       90.0  30.3                                                 7.5     43.3       80.0  18.0                                                 15.0    5.7        41.7  none                                                 30.0    7.3        51.7  none                                       2         15.0    93.3       53.3  49.7                                                 30.0    80.0       63.3  47.7                                                 60.0    49.0       93.3  32.3                                       3         0.25    100.0      20.0  47.7                                                 0.50    93.3       80.0  48.0                                                 1.0     76.7       93.3  47.0                                                 2.0     61.7       56.7  33.0                                                 4.0     23.3       20.0  none                                       4         1.88    60.0       90.0  48.3                                                 3.75    63.3       93.3  46.0                                                 7.5     38.3       58.3  47.7                                                 15.0    21.7       71.7  34.3                                                 30.0    15.7       31.7  none                                       5         5.0     91.7       66.7  47.3                                                 10.0    51.7       66.7  32.3                                                 20.0    31.7       35.0  32.0                                                 40.0    17.7       58.3  36.3                                                 80.0    7.3        15.0  none                                       7         15.0    35.0       75.0  30.3                                                 30.0    66.7       40.0  47.7                                                 60.0    55.0       58.3  34.3                                       9         15.0    95.0       38.3  47.0                                                 30.0    68.3       38.3  46.3                                                 60.0    61.7       61.7  51.0                                       10        36.5    86.7       60.0  45.3                                                 73.0    80.0       41.7  49.0                                                 146.0   73.0       3.3   33.7                                       Control   0       82.0       58.2  44.1                                       ______________________________________                                    

The compounds of this invention are useful for inhibiting pollenformation in cereal grain plants which are sensitive to such treatment,and the compositions in which the compounds are formulated forapplication, and the methods by which the compounds are applied toobtain the inhibition of pollen formation, constitute embodiments of theinvention.

A compound must be supplied to the plant before the maturation ofanthers. It must be noted that the head of a plant matures over a periodof time, and different plants in a field mature at different times.Accordingly, a compound must be supplied before anther maturation in themost mature plants in the field to be treated, if best results are to beobtained.

In wheat anther maturation occurs while the plant's head is about 5-10mm long. Thus, it is advisable to dissect representative plants fromtime to time to determine when development of the head, and therefore ofthe anthers, is approaching. Best results are obtained by supplying thecompound when the head is less than 5-10 mm long. Comparable indicationsof development in other species are used to determine the proper timefor treatment.

The compound must be supplied, not merely applied, to the plant beforeanther maturation. In this document, the term "supplying" is used tomean administering the compound in such a manner that it is absorbed bythe plant and is available to the target organs. In all cases, thecompound must be applied sufficiently early that it is absorbed andsupplied to the plant before anther maturation.

In the practice of the present invention, it is necessary to apply aneffective amount of a compound of the invention to the plant or the soilin which it grows. Effective amounts can be measured in terms of theconcentration of the compound in a dispersion, when the compound isapplied to the foliage, or, preferably, can be measured in terms of theamount of compound applied per unit area of land. The concentration ofthe compound is a useful measurement, because the amount of compoundapplied to foliage is limited by the amount of the dispersion which isretained by the foliage. That amount is substantially constant, for agiven size of plant, and therefore the amount of compound applied bythat means can be increased only by increasing the concentration of thedispersion. Depending on the circumstances, effective concentrations ofcompounds range from about 10 to about 100 parts per million by weight.Factors which affect the effective amount include the succulence of thefoliage, the rate at which it is growing, and the weather at the time ofapplication. In general, preferred concentrations for foliarapplications are in the range from about 50 to about 1000 parts permillion by weight.

Measurement of the amount of compound applied as a dose per unit area ofland may be used for either application to the soil or application tothe foliage. Of course, it will be understood that application to thefoliage results in some soil application in all cases, since not all ofthe composition applied to the foliage adheres there. In general, ratesof from about 0.1 to about 10 pounds of compound per acre of crop landare useful. It is more preferred to use rates from about 0.5 to about 10pounds per acre, most preferably, from about 0.5 to about 5 pounds peracre of the most preferred compounds.

It has been observed that application of the compound in multiple dosesprovides better effectiveness, and there is some indication that asmaller total amount of compound can effectively be used when applied inmultiple doses. It may be that the result is explained by the fact thatnot all plants form anthers at the same time, and multiple applicationsavoid the necessity for compounds to be stored for a long period in theplant or soil. Application of a compound from 2 to 4 times, at intervalsof 3 to 10 days, is preferred.

More particularly, application of a compound of the invention 2 or 3times, where each application is of from about 0.125 to about 2 poundsof compound per acre, applied to the foliage, is particularly preferred.Further, application of the compound 2 or 3 times, where eachapplication is of a dispersion containing from about 10 to about 250parts per million by weight of compound, and the dispersion is appliedso as to cover the foliage of the plants, is also preferred.

Another particularly preferred method of application of a compound ofthe invention is application to the soil in which the plants grow at arate of from about 0.5 to about 5 pounds of compound per acre, appliedonce.

The plants to which a compound of the present invention may be appliedto inhibit pollen formation are the cereal grain plants. A preferredgroup of species include wheat, barley, corn, rye and triticale. Themore preferred species of plants are wheat and barley, and the mostpreferred species is wheat.

More particularly, the plants to which the invention is applied aredefined as those which are sensitive to such treatment; that is, thosein which the compounds will inhibit pollen formation when properlyapplied. The plants are defined in that manner because considerablevariation in activity between varieties, and between individuals withina variety, has been observed. In barley, for example, some varietiesrequire several times as much compound for activity as do othervarieties.

In other species, of which corn is a particularly good example, thedifferences in sensitivity to the compounds are more subtle thanvarietal differences. It is therefore necessary, in such a species, toscreen for sensitive plants, and to use the seed produced by thoseplants to create a variety of sensitive plants for further use inhybridization.

Of course, some experimentation is needed to use the present inventionproperly, particularly in species such as corn. The experimentation,however, is well understood and routinely carried out by plant breeders.The nature of the tests is clearly shown above in the test portion ofthis document, and so the skilled reader can readily plan routineexperiments which will identify sensitive plants or varieties anddetermine the proper application rate of a compound, by the ordinaryskills of the art, and the teaching in this document.

A further aspect of the present invention is the production of hybridseed by use of the present pollen formation inhibiting method. Seed ofthe varieties which will be the male and female parents is planted inseparate but adjacent plots. The female parent variety, of course, mustbe sensitive to the treatment of the present invention. The size andlocation of the plots may be important. Some species, such as wheat andbarley, do not produce great quantities of pollen, as corn does, and sothe pollen cannot be expected to travel very far and still fertilize ahigh percentage of the female plants. Therefore, the female plots shouldbe relatively narrow. For example, the female and male parent seed mayusefully be planted in long alternate plots, only a few rows wide, withtheir long axes oriented across the prevailing wind.

It has been observed to be advantageous to plant the female parentvariety seed densely enough to inhibit the plants from developingtillers. The reason is that tillers develop later than the main plants,and therefore their presence confuses the determination of the propertime to apply the compound.

At the proper time, as discussed above in detail, the compound isapplied to the female parent plots to inhibit those plants fromproducing pollen. Those plants are then pollinated by the male parentplants and produce hybrid seed, which is harvested in the usual ways.

The compositions in which a compound of the present invention may beformulated are of many types. Since the compounds are effective whenapplied both to the foliage of the plants, and to the soil in which theplants grow, substantially all of the physical types of agriculturalchemical compositions may be used.

Most economical and preferred compositions are concentratedwater-emulsifiable or water-dispersable compositions. Such compositionsinclude, in general, emulsifiable concentrates, suspension concentratesand wettable powders and granules, all of which are common in theagricultural chemical art. Some discussion of them will be provided,however, to assure complete understanding.

The concentration of a compound in a concentrated composition isentirely irrelevant to the use of the compound. Such compositions arediluted in water for application, and the application rate of thecompound is determined by the ratio at which the composition is dilutedin water, or by the amount of the composition which is applied per areaof crop land. Thus, any desired application rate can be obtained fromany concentrated composition. Farmers and agricultural chemists areacquainted with the simple calculations which are necessary.

Emulsifiable concentrates of the compounds comprise a convenientconcentration of the compound dissolved in a phytologically-acceptablediluent which is a mixture of water-immiscible organic solvent andemulsifiers. Useful organic solvents, in general, include aromatics,especially xylenes, and the petroleum fractions, especially thenapthalenic and olefinic portions of petroleum, such as those calledheavy aromatic naphthas. Terpenic solvents including rosin derivatives,and complex alcohols such as 2-ethoxy ethanol are also often used, andamides such as dimethylacetamide may be particularly useful with thepresent compounds. Suitable emulsifiers for emulsifiable concentrates,generally used in amounts in the range of from about 1% to about 10% byweight of the concentrate, are frequently found among thealkylbenzenesulfonates, the alkyl sulfates, the non-ionics such asethylene oxide adducts of alkyl phenol, and especially among the metaland amine salts of alkyl sulfates.

Wettable powders comprise an intimate mixture of the compound and aphytologically-acceptable diluent made up of an inert carrier andsurfactants. The inert carrier is usually chosen from among easilywater-dispersable powdery substances such as attapulgite clay, themontmorillonite clays, the diatomaceous earths and the purifiedsilicates. Surfactants for wettable powders are found among the sametypes just mentioned for emulsifiable concentrates, as well as thesulfonated lignins and the naphthalenesulfonates. It is possible tocompact a wettable powder into granular form, and thereby to produce awettable granule, which has the advantage of being non-dusty and easy tomeasure and pour. When added to water, a properly formulated wettablegranular product will disperse and become a fine suspension.

The compounds may also be formulated as suspensions, which consist of arelatively high concentration, in the interest of economy, of thecompound in finely powdered form, dispersed and suspended in aphytologically-acceptable aqueous diluent. A surfactant system for asuspension product is much like that used in a wettable powder, but itmust be capable of maintaining the compound in dispersed form over along period of time. It is sometimes advisable to adjust the density ofthe liquid, as by dissolving an inert salt in it, in order to assist inthe suspension of the relatively dense particles of compound.

When an aqueous dispersion of a compound, prepared by the dilution of aconcentrated composition, is to be applied to foliage, an adjuvant isoften used to improve the ability of the dispersion to wet and adhere tothe foliage. Such adjuvants as vegetable gums, emulsified polybutenes,cationic and other surfactants and lignin derivatives are often used.The use of an adjuvant in aqueous dispersions of the present compoundsis highly preferred, and regularly improves results. Not only thecommercial adjuvants, which are commonly known to growers, but alsoordinary surfactants, are beneficially used, at concentrations in therange of a few tenths of a percent in the dispersion.

Aqueous dispersions of concentrated compositions may be applied eitherto foliage or to the soil in which plants grow. When the application isto be to the soil, a granular composition can also be effectively used.A granular agricultural composition consists of the compound, applied,usually in a relatively low concentration such as from about 1 to about10% by weight, to a granular carrier having a convenient particle sizefor application. Typically, the particle size range is from 20 to 60mesh, on the standard U.S. sieve size scale. Such carriers as clay,sand, pulverized stone, corncob grits and the like are frequently usedand may be chosen for convenience and economy. It is usually unnecessaryto use any adjuvant or other ingredient other than the compound and thecarrier, with perhaps a small amount of solvent in which the compound isapplied to the carrier. The carrier may also be supplied in powderedform, and formulated by mixing the powdered carrier with the powderedcompound and then compacting the mixture and granulating it to thedesired particle size range.

The following specific examples of formulations of compounds of thepresent invention are provided to assist the reader. It will beunderstood that the following formulations are merely exemplary of themanners of formulating the compounds. An agricultural chemist, using thefollowing formulations as guides, can readily prepare any desired typeof formulation, using any of the compounds of the invention as theactive ingredient.

    ______________________________________                                        Composition 1                                                                                      50% Wettable Powder                                      ______________________________________                                        compound of Example 1                                                                              51.6%                                                    lignin sulfonate     5.0                                                      precipitated silica  5.0                                                      sodium alkylbenzene sulfonate                                                                      5.0                                                      kaolin clay          33.4                                                     ______________________________________                                    

All of the ingredients were mixed, ground through a hammermill andfinely ground in an air impact mill.

    ______________________________________                                        Composition 2                                                                                      50% Wettable Powder                                      ______________________________________                                        compound of Example 2                                                                              51.6%                                                    lignin sulfonate     5.0                                                      precipitated silica  5.0                                                      sodium alkylbenzene sulfonate                                                                      5.0                                                      kaolin clay          33.4                                                     Composition 3                                                                                    0.5% Granules                                              ______________________________________                                        compound of Example 1                                                                            0.52%                                                      nonionic surfactant                                                                              0.02                                                       white mineral oil  0.18                                                       granular limestone 99.28                                                      ______________________________________                                    

The compound was finely ground, added to the limestone in a rotatingdrum, and the other ingredients were added as a fine spray.

    ______________________________________                                        Composition 4                                                                                    0.5% Granules                                              ______________________________________                                        compound of Example 2                                                                            0.52%                                                      nonionic surfactant                                                                              0.02                                                       white mineral oil  0.18                                                       granular limestone 99.28                                                      ______________________________________                                        Composition 5                                                                                   0.4% Granules                                               ______________________________________                                        compound          0.4%                                                        30/60 mesh attapulgite                                                                          99.6%                                                       ______________________________________                                        Composition 6                                                                                   1% Granules                                                 ______________________________________                                        compound          1.03%                                                       30/60 mesh attapulgite                                                                          98.97%                                                      ______________________________________                                        Composition 7                                                                                   2% Granules                                                 ______________________________________                                        compound          2.06%                                                       30/60 mesh attapulgite                                                                          97.94%                                                      ______________________________________                                        Composition 8                                                                                   4% Granules                                                 ______________________________________                                        compound          4.12%                                                       30/60 mesh attapulgite                                                                          95.88%                                                      ______________________________________                                        Composition 9                                                                                   5% Granules                                                 ______________________________________                                        compound          5.15%                                                       30/60 mesh attapulgite                                                                          94.85%                                                      ______________________________________                                        Composition 10                                                                                  10% Granules                                                ______________________________________                                        compound          10.31%                                                      30/60 mesh attapulgite                                                                          89.69%                                                      ______________________________________                                        Composition 11                                                                                  15% Granules                                                ______________________________________                                        compound          15.46%                                                      30/60 mesh attapulgite                                                                          84.54%                                                      ______________________________________                                    

All of compositions 1-11 are prepared by dissolving the compound in anappropriate amount of dimethylformamide and impregnating the carrierwith the solution. The solvent is then evaporated, at high temperatureif necessary.

    ______________________________________                                        Composition 12                                                                                  lb./gal. Suspension                                         ______________________________________                                        compound            12.1%                                                     Pluronic P-104 (non-ionic                                                                         1.0%                                                      surfactant)                                                                   silicone antifoam   0.2%                                                      propylene glycol    6.0%                                                      magnesium aluminum silicate                                                                       1.0%                                                      xanthan gum         0.1%                                                      water               79.6%                                                     ______________________________________                                    

The compound is ground with the P-104, the antifoam and part of thewater in an attrition mill for 45 minutes, and is then mixed with therest of the ingredients.

    ______________________________________                                        Composition 13                                                                                  25% Wettable Powder                                         ______________________________________                                        compound            26.9%                                                     sodium salt of lignin                                                                             10.0%                                                     with anionic wetting agents                                                   purified silica     10.0%                                                     kaolin clay         53.1%                                                     ______________________________________                                    

The above ingredients are thoroughly mixed, and the mixture is thenmilled through a hammermill and then through an air impact mill.

    ______________________________________                                        Composition 14                                                                                  0.5 lb./gal. Suspension                                     ______________________________________                                        compound            6.2%                                                      Tergitol TMN-6 (non-ionic                                                                         5.0%                                                      surfactant)                                                                   purified silica     0.5%                                                      silicone antifoam   0.1%                                                      2% xanthan gum      5.0%                                                      water               83.2%                                                     ______________________________________                                    

The compound is ground with part of the water, the silica and theantifoam in an attrition mill until 50% of the particles are smallerthan 1 micron by microscopic inspection, and the suspension is thenmixed with the rest of the ingredients.

    ______________________________________                                        Composition 15                                                                1 lb./gal. Suspension                                                         ______________________________________                                        compound              12.1%                                                   Tergital TMN-6        1.0%                                                    Polyfon H (lignin and sulfonate                                                                     2.0%                                                    salt)                                                                         5% magnesium aluminum silicate                                                                      20.0%                                                   suspension                                                                    2% xanthan gum suspension                                                                           0.2%                                                    silicone antifoam     0.2%                                                    water                 59.7%                                                   ______________________________________                                    

The compound is ground in an attrition mill with the Tergitol, thePolyfon and part of the water, and is then mixed with the rest of theingredients.

    ______________________________________                                        Composition 16                                                                1 lb./gal. Suspension                                                         ______________________________________                                        compound              12.1%                                                   Tergital TMN-6        1.0%                                                    Polyfon H             2.0%                                                    5% magnesium aluminum silicate                                                                      20.0%                                                   suspension                                                                    2% xanthan gum suspension                                                                           5.0%                                                    propylene glycol      6.0%                                                    silicone antifoam     0.2%                                                    water                 53.7%                                                   ______________________________________                                    

The compound is ground in an attrition mill with the Tergitol, thePolyfon and part of the water, and is then mixed with the rest of theingredients.

    ______________________________________                                        Composition 17                                                                1 lb./gal. Suspension                                                         ______________________________________                                        compound              12.1%                                                   Makon 12 (non-ionic surfactant)                                                                     1.0%                                                    5% magnesium aluminum silicate                                                                      20.0%                                                   suspension                                                                    2% xanthan gum suspension                                                                           5.0%                                                    silicone antifoam     0.2%                                                    water                 61.7%                                                   ______________________________________                                    

The compound is ground in an attrition mill with the Makon, the antifoamand part of the water and is then mixed with the rest of theingredients.

    ______________________________________                                        Composition 18                                                                1 lb./gal. Suspension                                                         ______________________________________                                        compound              12.1%                                                   Makon 12              1.0%                                                    propylene glycol      6.0%                                                    5% magnesium aluminum silicate                                                                      20.0%                                                   suspension                                                                    2% xanthan gum suspension                                                                           5.0%                                                    silicone antifoam     0.2%                                                    water                 55.7%                                                   ______________________________________                                    

The compound is ground in an attrition mill with the Makon, the antifoamand part of the water, and is then mixed with the rest of theingredients.

    ______________________________________                                        Composition 19                                                                1 lb./gal. Suspension                                                         ______________________________________                                        compound              12.1%                                                   Pluronic P-104        1.0%                                                    5% magnesium aluminum silicate                                                                      20.0%                                                   suspension                                                                    2% xanthan gum suspension                                                                           5.0%                                                    silicone antifoam     0.2%                                                    water                 61.7%                                                   ______________________________________                                    

The compound is ground in an attrition mill with the Pluronic, theantifoam and part of the water, and is then mixed with the rest of theingredients.

    ______________________________________                                        Composition 20                                                                5% Suspension                                                                 ______________________________________                                        compound              5.0%                                                    sodium napthaleneformaldehyde                                                                       3.0%                                                    condensate                                                                    30% formaldehyde      0.4%                                                    xanthan gum           0.4%                                                    propylene glycol      5.0%                                                    water                 86.2%                                                   ______________________________________                                    

The mixture is ground until the average particle size is 3 microns.

    ______________________________________                                        Composition 21                                                                5% Granules                                                                   ______________________________________                                               compound                                                                              5.0%                                                                  sand    95.0%                                                          ______________________________________                                    

The compound is dissolved in N-methylpyrrolidone, the appropriate amountof the solution is mixed with the carrier, and the solvent isevaporated.

We claim:
 1. A compound of the formula ##STR3## wherein R and R¹independently represent chloro, bromo or methyl;R² is hydroxy, C₁ -C₄alkoxy, C₃ -C₄ alkenoxy, C₃ -C₄ alkynoxy, or a phytologically-acceptablemoiety forming a salt of the carboxylic acid; R³ is NH₂, hydroxy, or aphytologically-acceptable moiety forming a salt of the carboxylic acid;or R² and R³ combine to form an imide; provided that R³ is NH₂ when R²is alkoxy, alkenoxy or alkynoxy; and that R² and R³ are the same when R³is other than NH₂.
 2. A compound of claim 1 wherein R² is hydroxy or aphytologically-acceptable moiety forming a salt of the carboxylic acid,and R³ is NH₂.
 3. A compound of claim 1 wherein R² is C₁ -C₄ alkoxy, C₃-C₄ alkenoxy or C₃ -C₄ alkynoxy.
 4. A compound of claim 1 wherein R andR¹ are the same.
 5. A compound of claim 2 wherein R and R¹ are the same.6. A compound of claim 5 wherein R and R¹ are chloro or methyl.
 7. Thecompound of claim 1 which is4-carboxy-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide or aphytologically-acceptable salt thereof.
 8. The compound of claim 1 whichis 4-carboxy-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamide or aphytologically-acceptable salt thereof.
 9. The compound of claim 1 whichis 4-methoxycarbonyl-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamide. 10.The compound of claim 1 which is1-(3,5-dichlorophenyl)-4-methoxycarbonyl-5-pyrazolecarboxamide.
 11. Apollen formation inhibiting composition comprising one or morephytologically-acceptable diluents and a pollen formation inhibitingamount of a compound of claim
 1. 12. A pollen formation inhibitingcomposition comprising one or more phytologically-acceptable diluentsand a pollen formation inhibiting amount of a compound of claim
 2. 13. Apollen formation inhibiting composition comprising one or morephytologically-acceptable diluents and a pollen formation inhibitingamount of a compound of claim
 3. 14. A pollen formation inhibitingcomposition comprising one or more phytologically-acceptable diluentsand a pollen formation inhibiting amount of a compound of claim
 6. 15. Apollen formation inhibiting composition comprising one or morephytologically-acceptable diluents and a pollen formation inhibitingamount of the compound of claim
 7. 16. A pollen formation inhibitingcomposition comprising one or more phytologically-acceptable diluentsand a pollen formation inhibiting amount of the compound of claim
 8. 17.A method of inhibiting pollen formation in a cereal grain plant which issensitive to such treatment comprising supplying to the plant at a timeprior to anther maturation a pollen formation inhibiting amount of acompound of claim
 1. 18. A method of claim 17 wherein the plant is awheat or barley plant.
 19. A method of claim 18 wherein the plant is awheat plant.
 20. A method of claim 17 wherein the compound is applied ata concentration of from about 10 to about 1,000 ppm.
 21. A method ofclaim 17 wherein the compound is applied in an amount of from about 0.1to about 10 lb/A.
 22. A method of claim 19 wherein the compound isapplied in an amount of from about 0.5 to about 5 lb/A.
 23. A method ofclaim 17 wherein the compound is4-carboxy-1-(3,5-dichlorophenyl)-5-pyrazolecarboxamide or aphytologically-acceptable salt thereof.
 24. A method of claim 17 whereinthe compound is 4-carboxy-1-(3,5-dimethylphenyl)-5-pyrazolecarboxamideor a phytologically-acceptable salt thereof.
 25. A method of claim 17wherein the compound is a compound wherein R² is hydroxy or aphytologically-acceptable moiety forming a salt of the carboxylic acid.26. A method of claim 17 wherein the compound is a compound wherein R²is C₁ -C₄ alkoxy, C₃ -C₄ alkenoxy or C₃ -C₄ alkynoxy.
 27. A method ofclaim 18 wherein the compound is a compound wherein R and R¹ are thesame and represent chloro or methyl.
 28. A method of claim 19 whereinthe compound is a compound wherein R and R¹ are the same and representchloro or methyl.